Feasibility of an interval, inspiration-triggered nocturnal odorant application by a novel device: a patient-blinded, randomised crossover, pilot trial on mood and sleep quality of depressed female inpatients

Abstract

It has been suggested that certain odorants positively affect mood, but this has not yet been scientifically tested in humans. The aim of the current study was to demonstrate the feasibility of a new odorant applicator and to assess the effects of nocturnal intermittent rose odorant application on mood, and quality of sleep and dreams in depressed female inpatients. We hypothesised that mood as primary outcome will improve. Twenty-seven normosmic, 18- to 49-year-old female, depressed inpatients were investigated in a randomised, placebo-controlled, crossover study. Exclusion criteria were rhinitis, hyp- or anosmia. During sleep, an interval-controlled, inspiration-triggered applicator added rose concentrate to the inspirated air. There were three consecutive nights of each odorant and placebo application and a wash-out phase. Patients completed standardised questionnaires on mood, dreams, and sleep quality. Four patients dropped out (n = 1: non-compliance in filling in the questionnaires, n = 3: intolerance of nasal tube). Otherwise, this novel odorant applicator was well tolerated. Application of the odorant showed no significant mood differences between rose and placebo, however, some subdomains of sleep quality and mood showed a positive trend towards improvement by rose application. The feasibility of this new device and of nasal tubes could be shown. Odorant application is well tolerated. It may have a positive influence on quality of mood and sleep in depressed patients. A longer application phase is planned to obtain convincing evidence for our hypothesis.

Nocturnal Olfactory Stimulation for Improvement of Sleep Quality in Patients With Posttraumatic Stress Disorder: A Randomized Exploratory Intervention Trial

“…After patients made several complaints about this device, we changed the odor (or placebo) stimulation for the second half of the patients to a lightweight and noninvasive nasal clip (aspiraclip; aspiraclip GmbH, Berlin, Germany). Both devices were new for application during the night—the olfactometer had been used in one study (Vitinius et al., ) and the nasal clip had not been evaluated thus far.…”

“…The olfactometer is a device that produces inspiration‐triggered air puffs every 30 s for 6 hr (for a detailed explanation, see Vitinius et al., ). An oxygen tube connected the patients’ nostrils to the machine and a piece of cotton wool that contained the odor (0.25 ml, without odor for the placebo group) was placed in the connection piece between the tube and device.…”

“…The advantage of this device is that it minimizes olfactory adaptation by presentation of inspiration‐triggered olfactory stimulation in intervals. Information about feasibility and tolerance of the treatment is still insufficient (Vitinius et al., ), and more data are required to prove its usefulness in clinical settings. The nasal clip is a light and small (3 mm inner diameter × 10 mm total size) half‐ring made out of medical silicone, with two pieces of cotton wool containing the odor (0.25 ml, without odor for the placebo group).…”

“…It is therefore not surprising that psychological disorders, such as depression or PTSD, are related to changes in olfactory perception (Croy & Hummel, 2017; Croy et al., ). In one study, nocturnal olfactory stimulation was applied in patients with depressive disorder; this did not lead to clear effects on sleep but rather to a positive trend toward an improved feeling of recovery and dream quality (Vitinius et al., ). In the current study, we explored the influence of nocturnal pleasant olfactory stimulation on objective and subjective sleep parameters in patients with PTSD.…”

Effects of aromatherapy with lavender essential oil on sleep quality among retired older adults

“…Lewith et al and Goel et al showed that aromatherapy with lavender essential oil improved sleep quality in people suffering from insomnia [11,12]. However, other studies have not reported the effects of lavender essential oil on sleep quality [13,14]. The available studies do not provide sufficient evidence to prove the hypnotic or sedative properties of lavender essential oil [15][16][17][18].…”